1. Field of the Invention.
The present invention relates to illuminated house number devices.
2. Description of the Related Art.
The need for an illuminated house number or letter device that can be readily installed in a house is apparent. Many times the house number can not be readily distinguished and it could even be dangerous if the dwelling identification constitutes an emergency.
Applicant believes that the closest reference corresponds to U.S. Pat. Nos. 982,352; 1,066,591 and 2,295,188 issued to Diehl, Ellis and Starnes, respectively. However, it differs from the present invention because the letters can not be readily connected to an existing transformer for annunciators across the typical momentary normally open switch. Also, the patented devices can not be both horizontally and/or vertically disposed without substantially modifying their connecting structure. Finally, even if these patented devices were connected across the switch contacts they would draw sufficient current to constantly activate the annunciator.
In U.S. Pat. No. 3,212,080 issued to Gurian, an electroluminescent panel controlled by a doorbell switch is disclosed where a step up transformer is required to bring the voltage up to 125 volts in its secondary. This, of course, requires considerable current in its primary which in turn acts as a shunt for switch 50. To work effectively the ratio of the impedance of the annunciator to the input impedance presented by the step up transformer has to be such that the voltage drop across the annunciator when switch 50 is open is below its threshold voltage. This limits severely the power capacity of the annunciator (requiring impedance to be low) and the load of the luminescent panel (requiring impedance to be high). Also, as in the other cited patents, the panel numbers can only be placed either horizontally or vertically but can not be readily changed from one position to the other one or any other slanted position.
Other patents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention.